Major industrial countries in the world now have regulations relating to the level of exhaust emissions from automobiles, which are imposing progressively reduced permitted levels of internal combustion engine emissions. This in turn increases the demand for greater control of the combustion process of the internal combustion engines.
U.S. Pat. No. 3,906,913 issued in September 1975 to the CALIFORNIA INSTITUTE OF TECHNOLOGY, discloses a device for mixing hydrogen with hydrocarbon fuel and air for use in the internal combustion engine of an automobile. However, such device requires a substantial "on-board" hydrogen generating capacity, to meet the large consumption of hydrogen, which consumes energy, occupies valuable space and adds weight to the vehicle.
U.S. Pat. No. 5,546,902 issued on Aug. 20, 1996 to the Australian company ORBITAL ENGINE COMPANY (AUSTRALIA) Pty, Limited, discloses a fuel/gas delivery system for use with an internal combustion engine, in which hydrogen is mixed with hydrocarbon fuel for introduction into the combustion chamber of the engine. In this patent, the hydrogen is delivered to the combustion chamber only when the engine is operating in a selected low to medium load range. Moreover, the injection of the hydrogen is enabled directly into the combustion chamber, which occurs independently and later than the fuel delivery; therefore, only relatively small amounts of hydrogen are required to achieve the desired improvement in the ignitability of the fuel/air mixture. Substantial improvement in the combustion process is claimed to be achieved with as little as 2% hydrogen injection in relation to the fuel charge. The low hydrogen usage thus enabled enhances the possibility of providing an economical means of producing sufficient quantities of hydrogen on-board an automobile. A claimed advantage is that the hydrocarbon (HC) and the toxic carbon monoxide (CO) contents of the exhaust gas are reduced, but not eliminated.